Immature Compost Suppresses Weed Growth Under Greenhouse Conditions

The influence of immature municipal solid waste-biosolids composts on emergence and mean days to emergence (MDE) of several weed species was evaluated in a pot trial under greenhouse conditions. The experiment consisted of placing a 7.5 cm deep layer of three-day-old immature compost, a mature and stable compost, an artificial medium or control sand as a mulch on ivyleaf morning glory seeds. Immature three-day-old compost decreased percentage emergence, shoot and root dry weight, and increased MDE of ivyleaf morning glory. In an experiment with eight-week-old immature compost utilizing mulching depths of 2.5, 5, 7.5, 10 cm and the untreated control on seeds of three weed species, common purslane did not emerge under any of the immature compost treatments. The MDE of ivyleaf morning glory and barnyard grass increased linearly as immature compost depths increased. Next, eight economically important weed species were sown in pots with either mature or immature (eight-week-old) compost utilizing mulching depths of 2.5 and 10 cm, in addition to an untreated control. Control pots yielded higher percentages of emergence than compost treatments for all species evaluated. Common purslane, large crabgrass, pig-weed, Florida beggarweed, and dichondra did not emerge through a 10-cm deep layer of mature compost mulch, or 2.5 or 10 cm deep layer of immature mulch. Significant compost maturity/depth interactions were observed for percent emergence on common purslane, ground cherry, large crabgrass, Florida beggarweed, and ivyleaf morning glory. A thinner layer was required to suppress germination using immature eight-week-old compost as compared to mature and stable compost. Immature (three-day or eight-week-old) compost containing acetic acid concentrations of 2474 and 1776 mg.kg^?1 respectively reduced percentage emergence of several economically important weed species. These studies suggest that immature composts can be used to control weeds under conditions where spatial separation is maintained between the crop and the compost and phytotoxic fermentation products do not affect the health of the mulched plants and where odors associated with such partially stabilized products do not pose problems.     

Biomass and Defoliation Tolerance of 12 Populations of Pseudoroegneria spicata at Two Densities

Pseudoroegneria spicata(Pursh.) A. Löve is an important native grass of the rangelands of the Intermountain West, USA and is widely used in this region for restoration applications. High grazing preference, together with high grazing sensitivity, has reduced the abundance of this species, indicating the need for the development of grazing-tolerant plant materials. While a genotype may be defoliation tolerant at low density, e.g., in an experimental setting, an effective grazing-tolerant genotype must also display this trait at higher densities resembling those found in natural and restoration settings. We compared 12 restoration plant materials for response to spring-defoliation at high (25 plants · m^?2) and low (8 plants · m^?2) plant densities in a field experiment. Two consecutive years of spring-defoliation reduced shoot biomass 19% compared to the nonspring-defoliated control, and this reduction was similar for the two densities examined. Two populations, P-3 and Acc:238, were able to compensate for shoot biomass after 2 yr of spring-defoliation, while the remaining 10 populations undercompensated, as is commonly reported for cool-season grasses in arid and semiarid regions. While the association between control and spring-defoliated shoot biomass was marginally positive (R² = 0.26; P < 0.10), we found a stronger negative association (R² = 0.36; P < 0.05) between spring-defoliation tolerance and control shoot-biomass production. This suggests a possible trade-off between growth and defoliation tolerance (calculated as percentage of control biomass) among populations. Of the four commercially available plant materials in our study, the more recent prevariety germplasm, P-7, exhibited higher control shoot biomass and higher spring-defoliation tolerance than the older cultivars, Whitmar and Goldar. Anatone germplasm was intermediate but not statistically different from these other plant materials for these two traits.     

Characterization ofSolanum tuberosum simple sequence repeats and application to potato culiwar identification

With the continued introduction of new potato cultivars, accurate identification is becoming difficult but is essential for maintaining cultivar integrity and Plant Breeders’ Rights. Hypervariable DNA sequences, referred to as simple sequence repeats (SSRs) or microsatellites, have been reported to be an excellent source of genetic markers. To determine the abundance, distribution, and composition of SSRs withinSolanium tuberosum, 252 sequences were searched for tetranucleotide and smaller SSRs with a minimum length of 20 nucleotides and a maximum discrepancy of two nucleotides. In total, 40 unique SSRs were observed in the 252S. tuberosum sequences examined and occurred at a frequency of one SSR every 8.1 kb. To assess the ability of site-specific amplified SSRs to identify potato cultivars, a simple (TCAC)_m and compound (TCAC)_m ? (CTT)_n SSR 5’ to the starch synthase gene and a compound (C)_p ? (CT)_q ? (AT)_r ? (G)_s SSR 5’ to the sequence encoding mature proteinase inhibitor I, were examined and shown to produce unique DNA profiles for 73 of 95 tetraploid cultivars. In total, 24 alleles were observed at these loci and the accurately sized amplified DNA products can be used to establish a database for cultivar identification. Site-specific amplified alleles were somatically stable and have been conserved in clonal variants of Russet Burbank independently maintained for almost seven decades, a characteristic essential for cultivar identification. As genetic markers, the abundant, informative, and easily examined site-specific amplified alleles of SSRs are ideal for quickly and accurately determining cultivar identity of S.tuberosum ssp.tuberosum.     

Modeling topographic effects on net ecosystem productivity of boreal black spruce forests

Current regional estimates of net primary productivity (NPP) of boreal black spruce overlook the large variation in NPP caused by small-scale topographic effects on soil water, temperature and nutrient availability. Topographic effects on black spruce NPP could likely be modeled by simulating the lateral and vertical movement of water, and its effects on soil nutrient transformation and uptake, through three-dimensional watersheds defined by aspects and slopes of their topographic positions. To examine this likelihood, the ecosystem model 'ecosys' was run for 120 years on a transect that included upper- and lower-slope positions and a basin in which a basal water table was set 0.5 m below the soil surface. For the run, we used soil properties and weather conditions recorded at the 115-year-old BOREAS Southern Old Black Spruce site. Short-term model performance was tested by comparing diurnal and annual carbon (C) transfers simulated under 1994 weather conditions during the 115th year of the model run with those measured at this site during 1994 by eddy covariance, surface chambers and allometry. After 115 years, annual spruce NPP simulated at the upper-slope positions was twice that at the basin (350 versus 170 g C m-2), whereas accumulated wood C was almost three times as large (6.8 versus 2.4 kg C m-2). In the model, increases in NPP and wood growth in upper-slope positions were caused by lower soil water contents, higher soil temperatures, and more rapid O2 uptake that accelerated heterotrophic respiration and hence nutrient mineralization and uptake. Modeled differences in wood growth with topographic position were quantitatively consistent with measurements of boreal black spruce at several research sites differing in water table depth. Modeled differences also agreed with differences in wood growth rates derived from allometric measurements at boreal black spruce sites differing in productivity indices as a result of differences in subsurface hydrology. The magnitude of these differences clearly indicates the importance of accounting for subsurface hydrology in regional estimates of boreal forest productivity.     

Detection of potentially allergenic hazelnut (Corylus avellana) residues in food: a comparative study with DNA PCR-ELISA and protein sandwich-ELISA

Allergen detection is of increasing interest for food labeling purposes. A comparative study with a commercial hazelnut-specific PCR-ELISA and a sandwich-type ELISA detecting hazelnut protein was performed to investigate to what extent immunochemical and DNA-based techniques would correlate in the detection of trace amounts of potentially allergenic hazelnut residues. Both methods were highly sensitive and allowed the detection of even <10 ppm of hazelnut in complex food matrixes. The protein-ELISA was highly specific for hazelnut. However, some foods could lead to false-positive results at the 10 ppm level. The PCR-ELISA did not show any cross-reactions with non-hazelnut foods, thus reducing the probability of having false positives at the trace level. Forty-one commercial food products with and without hazelnut components on their labels were analyzed for the presence of hazelnut. Of the 27 products in which hazelnut components were detected, two samples were not identified by the protein-ELISA, and only one sample, namely one white chocolate having <1 ppm of hazelnut protein, was not detected by PCR-ELISA. The good correlation of the results of PCR-ELISA and protein-ELISA suggested that both PCR-based and immunochemical techniques are suitable for reliable detection of potentially allergenic hazelnut residues in foods at the trace level.     

Cloning and sequence analysis of the complementary DNA for feline preproparathyroid hormone

OBJECTIVES: To clone and sequence the cDNA for feline preproparathyroid hormone (preproPTH) and to compare that sequence with other known parathyroid hormone (PTH) sequences. SAMPLE POPULATION: Parathyroid glands from 1 healthy cat. PROCEDURES: A cDNA library was constructed in lambda phage from feline parathyroid gland mRNA and screened with a radiolabeled canine PTH probe. Positive clones were sequenced, and nucleic acid and deduced amino acid sequences were analyzed and compared with known preproPTH and PTH sequences. RESULTS: Screening of approximately 2 X 10(5) recombinant plaques revealed 3 that hybridized with the canine PTH probe; 2 clones comprised the complete sequence for feline preproPTH. Feline preproPTH cDNA consisted of a 63-base pair (bp) 5'-untranslated region (UTR), a 348-bp coding region, and a 326-bp 3'-UTR. The coding region encoded a 115-amino acid peptide. Mature feline PTH consisted of 84 amino acids. Amino acid sequence analysis revealed that feline PTH was > 83% identical to canine, bovine, swine, equine, human, and macaque PTH and 69, 71, and 44% identical to mouse, rat, and chicken PTH, respectively. Within the region responsible for hormonal activity (amino acids 1 to 34), feline PTH was > 79% identical to other mammalian PTH sequences and 64% identical to the chicken sequence. CONCLUSIONS AND CLINICAL RELEVANCE: The amino acid sequence of PTH is conserved among mammalian species. Knowledge of the cDNA sequence for feline PTH may be useful to investigate disturbances of calcium metabolism and alterations in PTH expression in cats.     

Dissolved and colloidal phosphorus fluxes in forest ecosystems—an almost blind spot in ecosystem research

Understanding and quantification of phosphorus (P) fluxes are key requirements for predictions of future forest ecosystems changes as well as for transferring lessons learned from natural ecosystems to croplands and plantations. This review summarizes and evaluates the recent knowledge on mechanisms, magnitude, and relevance by which dissolved and colloidal inorganic and organic P forms can be translocated within or exported from forest ecosystems. Attention is paid to hydrological pathways of P losses at the soil profile and landscape scales, and the subsequent influence of P on aquatic ecosystems. New (unpublished) data from the German Priority Program 1685 “Ecosystem Nutrition: Forest Strategies for limited Phosphorus Resources” were added to provide up‐to‐date flux‐based information. Nitrogen (N) additions increase the release of water‐transportable P forms. Most P found in percolates and pore waters belongs to the so‐called dissolved organic P (DOP) fractions, rich in orthophosphate‐monoesters and also containing some orthophosphate‐diesters. Total solution P concentrations range from ca. 1 to 400 µg P L^?1, with large variations among forest stands. Recent sophisticated analyses revealed that large portions of the DOP in forest stream water can comprise natural nanoparticles and fine colloids which under extreme conditions may account for 40–100% of the P losses. Their translocation within preferential flow passes may be rapid, mediated by storm events. The potential total P loss through leaching into subsoils and with streams was found to be less than 50 mg P m^?2 a^?1, suggesting effects on ecosystems at centennial to millennium scale. All current data are based on selected snapshots only. Quantitative measurements of P fluxes in temperate forest systems are nearly absent in the literature, probably due to main research focus on the C and N cycles. Therefore, we lack complete ecosystem‐based assessments of dissolved and colloidal P fluxes within and from temperate forest systems.     

Plant Location Patterns in the European Automobile Supplier Industry

Motor vehicle and motor vehicle parts production tend to exhibit a strong degree of agglomeration. We estimate a location model utilizing detailed plant‐level data for over 1,700 European locations of the largest motor vehicle parts suppliers, as well as the location of all light vehicle assembly plants operational in 2010. This unique data set allows us to estimate a location model for the region at a significantly higher level of resolution than the previous literature. The results suggest that the main forces of agglomeration in the European auto supplier sector are highway access and the desire to locate near assembly plants as well as near other parts‐producing plants.     

SONOGRAPHY OF THE EQUINE PALMAR METACARPAL SOFT TISSUES

It was hypothesized that ultrasonography may be a sensitive method for identifying pathologic changes in the tendons and ligaments of the palmar metacarpus of the horse. The palmar meta-carpi of equine cadavers and live horses were examined sonographically. The advantages and disadvantages of various ultrasound scanning techniques and the normal appearance of longitudinal and transverse palmar metacarpal sonograms are described.